CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > ANSYS Meshing & Geometry

[ICEM] Meshing problem in Formula one

Register Blogs Members List Search Today's Posts Mark Forums Read

Like Tree3Likes

Reply
 
LinkBack Thread Tools Display Modes
Old   January 15, 2013, 10:16
Default
  #61
Far
Super Moderator
 
Sijal
Join Date: Mar 2009
Location: Islamabad
Posts: 4,314
Blog Entries: 6
Rep Power: 43
Far will become famous soon enoughFar will become famous soon enough
Send a message via Skype™ to Far
Quote:
Originally Posted by diamondx View Post
i often get the same prism generation, did you try generating ONE big layer of prism instead, and dividing it ?
Why this not happen in T-Grid?
Far is offline   Reply With Quote

Old   January 15, 2013, 10:45
Default
  #62
Super Moderator
 
diamondx's Avatar
 
Ghazlani M. Ali
Join Date: May 2011
Location: Tokyo, Japan
Posts: 1,366
Blog Entries: 23
Rep Power: 21
diamondx will become famous soon enough
Quote:
Why this not happen in T-Grid?
Can't really tell... try to generate one layer on prism, then divide it in edit mesh tab, go to the prism section and you will find divide prism, see if you can get a better result.
Also in the screenshot that you showed us, the prism were generated after the surface meshingand without the volume mesh. if you generete the volume mesh then the prism i'm sure you will get a better looking prism layers. why ? i don't know
__________________
Regards,
New to ICEM CFD, try this document --> https://goo.gl/NEbygB
Ali
diamondx is offline   Reply With Quote

Old   January 15, 2013, 10:50
Default
  #63
Far
Super Moderator
 
Sijal
Join Date: Mar 2009
Location: Islamabad
Posts: 4,314
Blog Entries: 6
Rep Power: 43
Far will become famous soon enoughFar will become famous soon enough
Send a message via Skype™ to Far
I did prism generation after volume mesh. Tetra are not turned on...
Far is offline   Reply With Quote

Old   January 15, 2013, 10:52
Default
  #64
Super Moderator
 
diamondx's Avatar
 
Ghazlani M. Ali
Join Date: May 2011
Location: Tokyo, Japan
Posts: 1,366
Blog Entries: 23
Rep Power: 21
diamondx will become famous soon enough
ah ok... yeah doesn't look good there. how about the other option i suggested
__________________
Regards,
New to ICEM CFD, try this document --> https://goo.gl/NEbygB
Ali
diamondx is offline   Reply With Quote

Old   January 15, 2013, 10:55
Default
  #65
Far
Super Moderator
 
Sijal
Join Date: Mar 2009
Location: Islamabad
Posts: 4,314
Blog Entries: 6
Rep Power: 43
Far will become famous soon enoughFar will become famous soon enough
Send a message via Skype™ to Far
Quote:
Originally Posted by diamondx View Post
ah ok... yeah doesn't look good there. how about the other option i suggested
I will try it. But T-grid is awesome
Far is offline   Reply With Quote

Old   January 15, 2013, 12:04
Default
  #66
Super Moderator
 
diamondx's Avatar
 
Ghazlani M. Ali
Join Date: May 2011
Location: Tokyo, Japan
Posts: 1,366
Blog Entries: 23
Rep Power: 21
diamondx will become famous soon enough
i generated my first volume mesh yesterday with the tutorials. it is really fast !!!
__________________
Regards,
New to ICEM CFD, try this document --> https://goo.gl/NEbygB
Ali
diamondx is offline   Reply With Quote

Old   January 15, 2013, 12:06
Default
  #67
Far
Super Moderator
 
Sijal
Join Date: Mar 2009
Location: Islamabad
Posts: 4,314
Blog Entries: 6
Rep Power: 43
Far will become famous soon enoughFar will become famous soon enough
Send a message via Skype™ to Far
Do you need input mesh files ?
Far is offline   Reply With Quote

Old   January 15, 2013, 12:08
Default
  #68
Super Moderator
 
diamondx's Avatar
 
Ghazlani M. Ali
Join Date: May 2011
Location: Tokyo, Japan
Posts: 1,366
Blog Entries: 23
Rep Power: 21
diamondx will become famous soon enough
for this formula one ???
__________________
Regards,
New to ICEM CFD, try this document --> https://goo.gl/NEbygB
Ali
diamondx is offline   Reply With Quote

Old   January 15, 2013, 12:09
Default
  #69
Far
Super Moderator
 
Sijal
Join Date: Mar 2009
Location: Islamabad
Posts: 4,314
Blog Entries: 6
Rep Power: 43
Far will become famous soon enoughFar will become famous soon enough
Send a message via Skype™ to Far
Quote:
Originally Posted by diamondx View Post
for this formula one ???
This can be shared if needed. But I am talking about T-grid input files!
Far is offline   Reply With Quote

Old   January 15, 2013, 12:09
Default
  #70
Super Moderator
 
diamondx's Avatar
 
Ghazlani M. Ali
Join Date: May 2011
Location: Tokyo, Japan
Posts: 1,366
Blog Entries: 23
Rep Power: 21
diamondx will become famous soon enough
i have them... thanks
__________________
Regards,
New to ICEM CFD, try this document --> https://goo.gl/NEbygB
Ali
diamondx is offline   Reply With Quote

Old   January 15, 2013, 12:50
Default
  #71
Super Moderator
 
diamondx's Avatar
 
Ghazlani M. Ali
Join Date: May 2011
Location: Tokyo, Japan
Posts: 1,366
Blog Entries: 23
Rep Power: 21
diamondx will become famous soon enough
yesterday i got my hand on pointwise. it took me more than 30 min to know how to rotate the geometry as i wanted
__________________
Regards,
New to ICEM CFD, try this document --> https://goo.gl/NEbygB
Ali
diamondx is offline   Reply With Quote

Old   January 15, 2013, 13:05
Default
  #72
Far
Super Moderator
 
Sijal
Join Date: Mar 2009
Location: Islamabad
Posts: 4,314
Blog Entries: 6
Rep Power: 43
Far will become famous soon enoughFar will become famous soon enough
Send a message via Skype™ to Far
You are good enough. Even it took me weeks to know how to make the simple mesh in Gambit
Far is offline   Reply With Quote

Old   January 15, 2013, 14:39
Default
  #73
Senior Member
 
Join Date: Mar 2011
Location: Germany
Posts: 429
Rep Power: 12
cfd seeker is on a distinguished road
Far and Diamondx....generating one prism layer and then splitting it to further parts is not a good idea as it produces bad quality prisms(again told to me by Simon). Instead generate atleast three layers and then split them but this splitting operation is not designed to give you good quality rather it is there to save time as splitting operation takes less time than generating the same no. of layers in the initial mesh and also to get your desired wall y+.

Anyhow the procedure is....Edit Mesh>Split Prisms....here there are two options to split prisms i.e Fixed initail height and Unifrom ratio, first will option will ensure the fixed height of 1st layer and later will ensure the unifrom distribution of prisms. After this you can go to Move Nodes>Redistribute Prisms...here again there are two options i.e Fixed Initial height and Uniform ratio. This option redistribute the splitted layers to give you a nice growing and properly distributed mesh in the B.L
Far and diamondx like this.
cfd seeker is offline   Reply With Quote

Old   January 16, 2013, 06:29
Default
  #74
Senior Member
 
AB
Join Date: Sep 2009
Location: France
Posts: 323
Rep Power: 14
BrolY will become famous soon enough
All those tricks are explained in the ICEM tips and tricks document made by Simon, aren't they ?
There are some posts about the right procedure to create prism on this forum (again based on Simon's tricks and tips ). The way I have always used is this one :

1) surface mesh (patch dependent if your geometry is good enough, otherwise, patch independent by volume mesh then delete volume mesh). Don't forget the build topology
2) smooth until nothing the quality is good : very important to have a good volume mesh after and good prisms
3) volume mesh (delaunay AF+TGLIB)
4) smooth until nothing the quality is good
SAVE your project.

Then you go for prism :
1) try to create as many layers as you want and see if it works.
if not, try the option explains and the Simon's tips and tricks document
2) if it doesn't work, try what CFD Seeker said. you can try one prism layer splitted in as many you want, or 3 prisms layers then split.
It depends on how many prism layers you want. If you want only 5 prism layers, just create 1 and split it in 5 after. If you want 20 prism layers, then create 5 and split it after would be a better way.
BrolY is offline   Reply With Quote

Old   January 16, 2013, 10:37
Default
  #75
Retired from CFD Online
 
PSYMN's Avatar
 
Simon Pereira
Join Date: Mar 2009
Location: Ann Arbor, MI
Posts: 2,660
Blog Entries: 1
Rep Power: 38
PSYMN has a spectacular aura aboutPSYMN has a spectacular aura about
Sorry I have been so busy lately... Far emailed me and asked me to stick my head in, but this thread has moved a long way since then. I noticed 2 questions.

1) Yes, if you have some surfaces meshed with patch conforming before you run Octree, you can keep the patch conforming mesh... It is an option when you compute mesh. Change the pull down to "geometry and mesh" and select the parts where you want to keep the mesh.

2) If you assign prism to a surface, like that tire, it will stair step off as it approaches the edge. It does this to prevent a solution where you have all the prisms ending along one plane, particularly very thin prisms with pyramids sticking out into the tetra volume. The best solution is to include the side surfaces in your prism selection. Then prism will be full on the surface you want and will taper off on the adjacent surface.
__________________
-----------------------------------------
Please help guide development at ANSYS by filling in these surveys

Public ANSYS ICEM CFD Users Survey

This second one is more general (Gambit, TGrid and ANSYS Meshing users welcome)...

CFD Online Users Survey
PSYMN is offline   Reply With Quote

Old   January 16, 2013, 11:12
Default
  #76
Senior Member
 
Join Date: Mar 2011
Location: Germany
Posts: 429
Rep Power: 12
cfd seeker is on a distinguished road
Quote:
2) If you assign prism to a surface, like that tire, it will stair step off as it approaches the edge. It does this to prevent a solution where you have all the prisms ending along one plane, particularly very thin prisms with pyramids sticking out into the tetra volume. The best solution is to include the side surfaces in your prism selection. Then prism will be full on the surface you want and will taper off on the adjacent surface.
I didn't get this point...can some one among you guys Far, diamondx, broly explain it may be with some example and with some pics....
cfd seeker is offline   Reply With Quote

Old   January 16, 2013, 11:14
Default
  #77
Super Moderator
 
diamondx's Avatar
 
Ghazlani M. Ali
Join Date: May 2011
Location: Tokyo, Japan
Posts: 1,366
Blog Entries: 23
Rep Power: 21
diamondx will become famous soon enough
yeah i will, i have an example in my lab, let me get back to you later on this
__________________
Regards,
New to ICEM CFD, try this document --> https://goo.gl/NEbygB
Ali
diamondx is offline   Reply With Quote

Old   January 16, 2013, 12:27
Default
  #78
Super Moderator
 
diamondx's Avatar
 
Ghazlani M. Ali
Join Date: May 2011
Location: Tokyo, Japan
Posts: 1,366
Blog Entries: 23
Rep Power: 21
diamondx will become famous soon enough
@ cfd seeker, i came to lab i realized i flushed away the mesh i had sorry about that.
the stair step is a normal and it happen because the prisms have to end somewhere. if the surface with the prism is really important to you, you can add prism to surface next to it too so you extend where the stair step appear...
__________________
Regards,
New to ICEM CFD, try this document --> https://goo.gl/NEbygB
Ali
diamondx is offline   Reply With Quote

Old   January 16, 2013, 12:35
Default
  #79
Super Moderator
 
diamondx's Avatar
 
Ghazlani M. Ali
Join Date: May 2011
Location: Tokyo, Japan
Posts: 1,366
Blog Entries: 23
Rep Power: 21
diamondx will become famous soon enough
We've just made this thread as the most discussed one in the ansys meshing section. thanks to the love story between scipy and far ... congratulation.
__________________
Regards,
New to ICEM CFD, try this document --> https://goo.gl/NEbygB
Ali
diamondx is offline   Reply With Quote

Old   January 16, 2013, 16:17
Default
  #80
Far
Super Moderator
 
Sijal
Join Date: Mar 2009
Location: Islamabad
Posts: 4,314
Blog Entries: 6
Rep Power: 43
Far will become famous soon enoughFar will become famous soon enough
Send a message via Skype™ to Far
Quote:
Originally Posted by PSYMN View Post
Ys, if you have some surfaces meshed with patch conforming before you run Octree, you can keep the patch conforming mesh... It is an option when you compute mesh. Change the pull down to "geometry and mesh" and select the parts where you want to keep the mesh.
That is Compute mesh > Volume Meshing > Input > Use Existing Mesh Parts? Then these mesh parts will be skipped during octree mesh generation? And octree also ensures that the mesh is conformal with the already existing mesh.


Quote:
Originally Posted by PSYMN View Post
If you assign prism to a surface, like that tire, it will stair step off as it approaches the edge. It does this to prevent a solution where you have all the prisms ending along one plane, particularly very thin prisms with pyramids sticking out into the tetra volume. The best solution is to include the side surfaces in your prism selection. Then prism will be full on the surface you want and will taper off on the adjacent surface.
I need to create two surfaces perpendicular to the wheel surface?
Far is offline   Reply With Quote

Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Problem with querying the meshing database in CFX-Pre ashtonJ CFX 16 November 23, 2016 04:56
[Other] Hex meshing problem DM12 patrick ANSYS Meshing & Geometry 7 January 9, 2015 08:21
[GAMBIT] 3D boundary layer and meshing problem in GAMBIT 2.4.6 prashanthreddyh ANSYS Meshing & Geometry 1 December 20, 2011 01:35
[ICEM] Hexa meshing blocking problem fergal ANSYS Meshing & Geometry 0 June 28, 2011 10:01
Strange ANSYS Meshing 13.0 Problem brunob ANSYS Meshing & Geometry 3 June 21, 2011 20:03


All times are GMT -4. The time now is 17:32.